diff --git a/content/base/src/nsFrameLoader.cpp b/content/base/src/nsFrameLoader.cpp
index cb476425012d..dd0f98ee50c9 100644
--- a/content/base/src/nsFrameLoader.cpp
+++ b/content/base/src/nsFrameLoader.cpp
@@ -1888,6 +1888,11 @@ nsFrameLoader::EnsureMessageManager()
   if (NS_FAILED(rv)) {
     return rv;
   }
+
+  if (!mIsTopLevelContent) {
+    return NS_OK;
+  }
+
   if (mMessageManager) {
 #ifdef MOZ_IPC
     if (ShouldUseRemoteProcess()) {